There is an increasing interest for a method of so called retail activation. Optical recording media that are on display in a shop should not play properly unless they are properly bought, paid for, and then activated at the point of sales. The need for activation the optical recording media serves as a theft protection.
For example, it has been proposed to leave out some necessary data on the optical recording medium, without which the optical recording medium cannot play properly. These data are then recorded on the optical recording medium at the point of sales.
However, it is not possible to use this solution for read-only optical recording media.
As an alternative, US 2007/0116920 discloses an optical recording medium having an optical data layer for storing data. The data is read from the optical data layer in an activated state. Disposed on the optical data layer is a material capable of irreversibly undergoing a morphological transformation from a first morphology to a second morphology upon interaction with an external stimulus. The morphological transformation alters the state of the optical recording medium from a pre-activated state to the activated state.
This solution is applicable to read-only optical recording media and offers some protection against theft. However, there is a problem that the external stimulus necessary for inducing the morphological transformation may also be applied by an illegitimate possessor after the theft of the optical recording medium.
US 2006/0114755 discloses a read-only optical recording medium having a an area provided with a light-sensitive layer. The light-sensitive layer is applied to a reading side of the optical recording medium and changes its reflectivity upon illumination. The light-sensitive layer blocks incoming light so that the optical recording medium is unplayable before an activation process.